Local Ionic Displacements and Polarization at the Paraelectric‐Ferroelectric Heterointerface: Effect of Octahedral Distortion

Abstract

At the ferroelectric ABO3 perovskite heterointerface, the broken translational symmetry significantly alters the octahedral network and cation sublattices. Experimentally revealing the interaction between the polarization and atomic structure parameters is beneficial not only for understanding the novel physical phenomena but also for realizing exotic physical functionalities at the materials surface science. Here, it is demonstrated that the induced polarization can be realized by the cooperative interaction between the octahedral distortion and the cation sublattices at the paraelectric‐ferroelectric heterointerface in the (K,Na)NbO3 epitaxial thin film. It is found that the cation–cation displacement scales with the tetragonality of the perovskite unit cell but not with the polarization, which is minimal in the substrate but increases substantially in the thin film. Nevertheless, the oxygen octahedral distortion in the substrate, accompanied by octahedral rotation, is stronger than that in the film, resulting in a translated and stable polarization across the interface. These results demonstrate the octahedral network plays a significant role in the ferroelectric polarization and can also greatly advance the understanding of the heterointerface science for ferroelectrics.

Development status of optical-electrical-magnetic high-flux coupling materials

“…LOOCV and the test set had classification accuracies of 87.29% and 86.21%, respectively. The regression models were then built using two machine learning methodologies, SISSO and Machine-Learning Workflow, to predict the band gap (Eg), specific surface area (SSA), dielectric loss (tan δ) of ABO3-type perovskites, and Curie temperature (Tc) [46] . The LOOCV correlation coefficients in the best models for SSA, Eg, and Tc are 0.935, 0.891, and 0.971, respectively, but the correlation coefficient between the SISSO model's anticipated and observed values for predicting tan may reach 0.913.…”